In various image pickup devices such as a video camera and a still camera, an optical system including a lens group and an optical element and an image pickup element for photoelectrically converting light taken by the optical system are arranged. When an object is photographed, light enters the image pickup element via a focal plane shutter which functions as a blade opening and closing device.
There is a blade opening and closing device including first opening and closing blades, second opening and closing blades, a base body in which an opening has been formed, a first magnetic driving unit for moving the first opening and closing blades, and a second magnetic driving unit for moving the second opening and closing blades (for example, refer to Patent Document 1).
In such a blade opening and closing device, the first opening and closing blades and the second opening and closing blades are respectively moved by the first magnetic driving unit and the second magnetic driving unit in each mode in a predetermined state. A first magnet, a first coil, and a first yoke are provided in the first magnetic driving unit, and a second magnet, a second coil, and a second yoke are provided in the second magnetic driving unit. Currents are supplied to the first coil and the second coil, and the first opening and closing blades and the second opening and closing blades are separately moved.
When the object is photographed, a slit travel for moving the first opening and closing blades and the second opening and closing blades in the same direction is performed. At the time of the slit travel, the first opening and closing blades and the second opening and closing blades are moved in a state where a slit having a predetermined width is formed between the first opening and closing blades and the second opening and closing blades, and light passed through the slit and the opening enters from one of imaging surfaces of the image pickup element to the other imaging surface in order so that exposure is performed.
The light entered at the time of the slit travel is sequentially photoelectrically converted by the image pickup element to generate an image signal, and the generated image signal is transferred to a memory to generate an image of the object.